Crankcase drain plug wrench



Feb. 13, 1962 W. A. DAVIS CRANKCASE DRAIN PLUG WRENCH Filed Sept. 4,1959 Wilbur A. Davis INVENTOR.

3,020,790 Patented Feb. 13, 1962 3,020,790 CRANKCASE DRAIN PLUG WRENCHWilbur A. Davis, Mahomet, 111., assignor of five percent to Howard F.Wagner and Dorothy M. Wagner, jointly, both of Champaign, IlL, andtwelve percent to Rivard Brothers Inc., Glenview, 11]., a corporation ofIllinois Filed Sept. 4, 1959, Ser. No. 838,118 Claims. (Cl. 81119) Thepresent invention relates to a novel and improved wrench which isadapted to be used manually and which is expressly constructed anddesigned to facilitate the removal of a bolt-type plug (sometimes calleda screw plug) from the usual threaded drainage hole in a crankcase, forexample, the crankcase commonly associated with the engine of anautomobile.

More specifically, the Wrench, that is the several embodiments hereinunder consideration, is a rigid sheet metal or an equivalent type whichis characterized by a plate of elongated form and which is slipped intoplace after the bolt has been initially loosened. The plate haslengthwise flanges which are of requisite length and which are laterallydisposed relative to the surface of the plate which contacts the bolt,said flanges serving as wedging and friction gripping jaws. A pull'cordis attached to the plate of the wrench so that by winding the" cordaround the shank'of the bolt and pulling on thecord it will cause arotation of the wrench and will remove the bolt-plug.

One improvement resides in utilizing elongated flanges which convergetoward one end of the plate and which flanges also slope toward eachother and a central longitudinal portion of the plate to overhang theplate to provide a Wedging and secure retaining action so that the boltwill wedge itself tightly between the jaws and will not slip or fall outafter it is removed from the crankcase.

The invention features, as mentioned, several adaptations or embodimentsof the broad idea, that is of an elongated plate having opposedcooperating jaw-forming flanges. these embodiments one from the otherwill, however, be passed over at this stage and will be set forth inproper detail in the following specification.

Other objects, features and advantages will become more readily apparentfrom the following description and the accompanying illustrativedrawing.

In the drawing wherein like numerals are employed to designate likeparts throughout the views:

FIG. 1 is a view in perspective of the improved wedge action spin-typewrench illustrating how it is constructed and intended to be used.

FIG. 2 is a view on a larger scale which shows the crankcase in section,the drain plug or bolt in elevation and the wrench in section andapplied to the head of the bolt.

FIG. 3 is a view on an enlarged scale and showing the improved wrench inperspective.

FIG. 4 is also a view in perspective but showing a modified embodimentof the wrench.

FIG. 5 is another perspective view on a smaller scale showing a furthermodification.

Reference will be made first to FIGS. 1 to 3 inclusive and particularlyto FIG. 3. In this figure the aforementioned elongated fiat faced plateis of requisite length and width and the median or body portion 6 iswide at the right-hand end portion 8 and gradually narrows toward theleft hand end portion 10, the lengthwise edges being provided withopposed duplicate friction gripping flanges 12. These flanges correspondin length and are limited to the median portion and they converge towardthe left hand end. Contrawise these flanges diverge to- The particularsand features which distinguish ward the right-hand end. With the flangesterminating short the end portions 14 and 16 project in the mannershown. The alternate edge portions of 14 and 16 are provided withreinforcing laterally bent lips 18 and 20. A suitable hole or opening isprovided at 22 and one end of a pull rope or cord is passed through thehole and formed into a knot 24 and is thus anchored in place. The freeend portion of this pull cord (used for spinning and whipping thewrench) is denoted by the numeral 26. Not only do the flanges or jaws l2slope inwardly toward the lengthwise median portion of the plate theedges actually overhang the plate. Moreover the cross-section of theflanges is preferably proportional with the head 28 of the screw-plug orgrain bolt as brought out in FIG. 2. The shank or stem of the bolt 30 isthreaded into the drain hole 32. Incidentally, the crankcase is denotedat 34 in FIG. 2 and this figure brings'out the cooperative associationof the wedging and friction gripping jaws with the peripheral portion ofthe head 28 of the bolt. The crosssection is preferably such that thewedge-like receptacle formed by the plate and jaws is deeper than thethickness or cross-section of the head 28. It follows that the edgeportions 36 actually project beyond the bolt head in the direction ofthe shank of the bolt as illustrated. The same basic principles underliethe modifications seen in FIGS. 4'and 5. In FIG. 4 for example theelongated flat faced plate is denoted by the numeral 38 and thelengthwise flange 40 extends the full length of the plate and is slopedso that the edge 42 overlies the cooperating thrust surface of theplate. Along the opposite longitudinal edge selectively usable flangesare provided. That is to say, one overhanging and sloping flange isdenoted at the right as at 44 and has its end 46 slanted inwardly towardthe median portion of the flange 40 to thus provide one wedge portion50. A similar wedge portion 52 is provided at the left hand end portionand this is defined in part by the other sloping and slanting flange 54.The end portion 56 of this flange also terminates at the central ormedian portion 48 of the plate and is inwardly inclined toward theflange 40. The wrench (FIG. 4) here under consideration is intended forholding bolt heads while tightening a nut on the bolts shank portion. Nostring is required.

In the modification seen in FIG. 5 the over-all wedgetype frictiongripping wrench is denoted by the numeral 62. Here the wedge-shaped flatfaced plate is denoted at 64 and at the center and on one side there isa cylindrical stud-like projection 66 to which the knotted end 68 of thepull cord or rope 76 is connected. In this instance the flanges arecommensurate with the length of the short plate and the flanges 72converge toward the right-hand end as denoted at 74. The flanges alsoslope toward each other so that the edge portions overhang thewedge-shaped plate 64.

In FIG. 5 the cylindrical member is a sawed-off form intended for use inremoving drain oil plugs on cars which have limited space between oilpan and tie rods and above all the body 64 and jaws 74 must be shortotherwise one gets a whip action in rotation. Therefore, its use islimited to possibly three bolt sizes only.

It will be evident from the construction shown that one wrench will fitmany or several different sizes of bolt heads. The sides of the jaws'are sloped to form a binding and frictionclamping action over the bolthead to prevent it from falling out of the wrench. When torque pressureis applied for a loosening action against the bolt head, due to theinitial resistance of the bolt, it will have a tendency to lock itselfin the wrench. The pull cord or rope in one case may be used as aspinning or wrench propelling device and in both cases it serves as ameans of not permitting the wrench or the bolt to drop into the oilreceiver. This pull cord is used to jerk the wrench free of the removedplug. The main application is where the wrapping and pulling of the ropewill create a rapid spin action. The wrench may be regarded asadjustable by push pressure to fit either square or hexagon shaped headson bolts or nuts. It can be used in the hand as a simple back-up wrench.It has been found to be adaptable for practical use on socalled foreignmake cars.

In addition to the above it may be added that this wrench was obviouslyprimarily designed to be used by service station attendants for changingcrankcase oil. It is designed to fit various sizes of bolts. Theattendant employs the wrench to Wedge the same properly on the bolt headand initially loosen the bolt, holds the cord in one hand and with theother hand spins the wrench to remove the bolt. This enables him toremove the plug or bolt without getting hot dirty oil on his person orhis work clothing and, of course, by hanging onto the cord, he will notlose the plug in the receiver in which the oil is trapped.

The foregoing is considered as illustrative only of the principles ofthe invention. Further, since numerous modifications and chanegs willreadily occur to those skilled in the art, it is not desired to limitthe invention to the exact construction and operation shown anddescribed, and accordingly all suitable modifications and equivalentsmay be resorted to, falling within the scope of the invention asclaimed.

What is claimed as new is as follows:

1. A manually usable wrench comprising an elongated plate having a flatsurface portion thereof designed to bear firmly against the head of abolt, the longitudinal edges of said plate having longitudinal flanges,said flanges converging lengthwise toward one end of the plate anddefining a wedge-like space between themselves into which the bolt headmay be moved to seat itself whereupon the flanges then jam upon andfrictionally grip the then lodged head and serve as jaws when torque isapplied, said flanges being relatively inclined and outwardly convergentto one side of said plate, and a flexible element having one end securedto said plate.

2. A manually usable wrench comprising an elongated plate having a flatsurface portion thereof designed to bear firmly against the head of abolt, the longitudinal edges of said plate having longitudinal flanges,said flanges converging lengthwise toward one end of the plate anddefining a wedge-like space between themselves into which the bolt headmay be moved to seat itself whereupon the flanges then jam upon andfrictionally grip the then lodged head and serve as jaws when torque isapplied, and a flexible element having one end secured to said plate,said flanges sloping toward each other at their outer free lengthwiseedges, at least one of said outer edges overhanging the adjacentmarginal edge portion of said plate.

3. The structure defined in claim 2 and wherein said flanges are ofequal length and are confined to the median portion of the plate withtheir ends spaced inwardly from the transverse end portions of saidplate.

4. The structure defined in claim 2 and wherein said flanges are ofequal length and are confined to the median portion of the plate withtheir ends spaced inwardly from the transverse end portions of saidplate, said lengthwise edges of said flanges being spaced from saidplate a distance greater than the thickness of the head of the bolt,whereby when the head is fully seated and gripped the free lengthwiseedges project beyond the head in a direction toward the shank of thebolt.

5. A manually usable Wrench comprising an elongated plate having a flatsurface portion thereof designed to bear firmly against the head of abolt, the longitudinal edges of said plate having longitudinal flanges,said flanges converging lengthwise toward one end of the plate anddefining a. wedge-like space between themselves into which the bolt headmay be caused to seat itself whereupon the flanges then jam upon andfrictionally grip the then lodged head and serve as jaws that is whenthe intended torque is applied, said flanges being commensurate inlength with the over-all length of the plate and having their edgeportions overhanging marginal edges of the plate, the median part of theplate on one side being provided with a stud and one end of a flexibleelement being secured to said stud.

6. A manually usable wrench comprising an elongated plate having a flatsurface portion thereof designed to bear firmly against the head of abolt, the longitudinal edges of said plate having longitudinal flanges,said flanges converging lengthwise toward one end of the plate anddefining a wedge-like space between themselves into which the bolt headmay be moved to seat itself whereupon the flanges then jam upon andfrictionally grip the then lodged head and serve as jaws when torque isapplied, and a flexible element having one end secured to said plate,one flange being of a length corresponding with the length of the plate,said flange being on one edge of the plate, there being a pair offlanges on the opposite edge of the plate and said last named flangeshaving their inner ends toward the median portion of the plate spacedapart and diagonally angled so that the portions of the plate onopposite sides of the median part of the plate constitutedistinguishably different wedge-shaped selectively usable wrenches.

7. A manually usable wrench comprising an elongated plate having a flatsurface portion thereof designed to bear firmly against the head of abolt, the longitudinal edges of said plate having longitudinal flanges,said flanges converging lengthwise toward one end of the plate anddefining a wedge-like space between themselves into which the bolt headmay be moved to seat itself whereupon the flanges then jam upon andfrictionally grip the then lodged head and serve as jaws when torque isapplied, one flange being of a length corresponding with the length ofthe plate, said flange being on one edge of the plate, there being apair of flanges on the opposite edge of the plate and said lastmentioned flanges having their inner ends toward the median portion ofthe plate, spaced apart and diagonally angled so that the portions ofthe plate on opposite sides of the median part of the plate constitutedistinguishably different wedge shaped selectively usable wrenches.

8. A manually usable wrench comprising an elongated plate having a fiatsurface portion thereof designed to bear firmly against the head of abolt, the longitudinal edges of said plate having longitudinal flanges,said flanges converging lengthwise toward one end of the plate anddefining a wedge-like space between themselves into which the bolt headmay be moved to seat itself whereupon the flanges then jam upon andfrictionally grip the then lodged head and serve as jaws when torqueaction is applied, said flanges being relatively inclined and outwardlyconvergent to one side of said plate.

9. A manually usable wrench comprising an elongated plate having a flatsurface portion designed to bear firmly against the head of a bolt, thelongitudinal edges of said plate having longitudinal flanges, saidflanges converging lengthwise toward one end of the plate and defining awedge-like space between themselves into which the bolt head may bemoved to seat itself whereupon the flanges then jam upon andfrictionally grip the then lodged head and serve as jaws when torque isapplied, one flange being of a length corersponding with the length ofthe plate, said flange being on one edge of the plate, there being apair of flanges on the opposite edge of the plate and said lastmentioned flanges having their inner ends toward the median portion ofthe plate, spaced apart and diagonally angled so that the portions ofthe plate on opposite sides of the median part of the plate constitutesdistinguishably different wedge-shaped selectively usable wrenches, theinner end of one of said last mentioned flanges being spaced closer tosaid one flange than the 1,306,553

inner end of the other of said last mentioned flanges. 1,855,586

References Cited in the file of this patent 2,640,382

UNITED STATES PATENTS 5 1,300,995 Moody .Apr. 15, 1919 125,021

6 Morrison June 10, 1919 Nordstrom Apr. 26, 1932 Grossman June 2, 1953FOREIGN PATENTS Great Britain Apr. 10, 1919

